Gramophone sound-box.



N0. B55,|95. I Patented Aug. 7, I900.

G. K. CHENEY.

" GBAMOPHONE SOUND BOX.

(Application filed Oct. 13, 1899.1

. (No Model.)

WITNESSES:

ATTORNEY s PETERS $0,. PH

UNITED STATES GEORGE K. CHENEY, OF NEW YORK,

N. Y., ASSIGNOR TO THE NATIONAL GRAMOPHONE CORPORATION, OF SAME PLACE.

GRAMOPHONE SOUND-BOX.

SPECIFICATION forming part of Letters Patent No. 655,195, dated August '7, 1900i Application filed October 18 1899. Serial No. 733,951. (No model.)

To all whom it" may concern.-

Be it known that I, GEORGE K. CHENEY, a citizen of the United States of America, and a resident of New York, county of New York, and State of New York, have invented certain new and useful Improvements in Sound-Reproducing Apparatus, of which the following is a specification.

My invention relates in general to talkingmachines; and it more specifically consists of an improved sound-box for talking-machines in which a triangular diaphragm is employed and in which the vibrating stylus is connected to the diaphragm by a universal joint.

The preferred form of apparatus embodying my invention is illustrated in the accompanying sheet of drawings, in which- Figure 1 is a front elevation of a sound-box embodying myinvention. Fig. 2 is a similar view with the retaining-plate and stylus removed. Fig. 3 is a side elevation of the soundbox, and Fig. 4 is a central section of the same.

Throughout the drawings like referencefigures refer to like parts.

The main portion of the sound-box has the hub 1 and the recessed portion 1. This recessed portion is triangular in shape, so as to receive atriangulardiaphragm 2. Preferably this diaphragm and the recess for the same are made in the shape of an equilateral triangle, as shown. The retaining-plate 3 is held in place to protect and retain the diaphragm by a series of screws4 4, or by equivalent method of fastening. This retaining-plate has an opening 5 of any convenient size and shape in its center, through which extends the connection from the diaphragm to the stylus. This stylus may beof any convenient form, but preferably consists of an arm or carrier 6, mounted on a yielding or spring arm 6 and carrying the stylus-needle 7, which is held in position by the set-screw 8. On the center of the diaphragm is mounted a socket-piece 9, which has the surrounding walls of the socket crimped in to retain the ball 10 of aballand-socket joint. The pin 11, connected to the ball 10, is screw-threaded and screws into an internally-threaded perforation in the end of the stylus. The diaphragm 2 may be held in position by any convenient arrangement of gaskets 12 12, as shownin Fig. 4.

The mode of operating my invention is as follows: The parts being assembled, as shown in Figs. 1, 3, and t, the connectionbetween stylus and diaphragm is properly adjusted by turning the ball 9 and threaded pin 11. When the stylus is vibrated by the needle? running along the groove of a sound-record, the vibrations are faithfully transmitted to the diaphragm 2 and reproduced as sound-waves of air in the sound-box.

The advantages of the invention comprise duction of the sound-waves by a diaphragm of the triangular shape shown, the convenience of adjustmentv of the stylus and diaphragm connection by simple turning of the screw 11, and the fact that the ball-and-socket joint adjusts itself immediately to all positions of the parts and permits the same to play freely in action, while preserving arigid connection along the line of transmission of motion. As a result the diaphragm responds easily and faithfully to every vibration of the stylus given toit by the sound-record and cannot become cramped or jammed by any variations in adjustment.

As to the triangular form of diaphragm I have found by experiment that the area of greatest vibration of a diaphragm tends in a majority of cases to assume the form of an equilateral triangle whose central point is the point of attachment of the vibrating stylus. I have observed this by exposing adiaphragm to rays of light whose reflection during vibration of the diaphragm would show accurately the area to which the vibrations were confined. I found that whatever the shape of the diaphragm the area of vibration was triangular in shape. It occurred to me, therefore, that a diaphragm triangular in shape would be more evenly and effectively vibrated for a given weight of material and area of surface than one of the usual circular form. Experiments have proved the correctness of this theory and resulted in the invention of the above-described apparatus.

Of course various changes could be made the louder, clearer, and more faithful reprovention.

in the details of construction shown without departing from the spirit and scope of my in- Other means of supporting the diaphragm might be employed. Other forms of universal joint connection and other means of adjustment, &c., might be substituted for those illustrated; but all such modifications I consider to be merely unimportant varia tions of form and still within the scope of my invention.

Having therefore described my invention,

'l what Iclaim as new, and desire to protect by Letters Patent, isp g 1. The combination of a diaphragm, astylus,and a ball-and-socket connection-between v the two.

2. In a talking-machine the combination of day of August, 1899.

a triangular diaphragmya stylus,,and an adj ustable ball-and-sooketconnection between the stylus and the center'ofthe diaphragm.

3. The combination of a'diaphragm, a stylus, andan adjustable ball-and-socket connection between the two.

4. The combination of a diaphragm,a stylus, and a ball-and-socket connectionwhich has its female member connected to the center of the diaphragm and its male. member adjustably connected to the stylus.

Signed by meat New York, N. Y., this 31st GEORGE CHENEY. Witnesses: H p

A. PARKER-SMITH,

M. TURNER.- 

